Indoor unit will not start cooling; display shows E0 shortly after power-on.

Safety first: Turn off the breaker to the indoor unit and wait at least 5 minutes before touching any wiring. Do not work on live circuits.

• Power reset: Turn the AC off at the remote, then switch off the dedicated breaker for 5–10 minutes. Restore power and test. Sometimes E0 clears after a full reset.
• Check indoor wiring harness: Remove the front cover of the indoor unit, then remove the control box cover. Inspect the multi-pin connectors between the display/IR board and the main PCB. Reseat each connector firmly and check for bent pins or corrosion.
• Inspect for surge damage: Look for burn marks, swollen capacitors, or a burnt smell on the indoor main PCB. If present, the board must be replaced.
• EEPROM / PCB replacement: If E0 returns immediately after reset and wiring is sound, the indoor main PCB (which includes the EEPROM on many Sharp models) is likely faulty. Label all connectors, remove the old board, install the new one, and reconnect exactly as before.
• When to call a technician: If you do not have experience with PCB replacement or if the unit requires EEPROM programming specific to your model, contact an authorized Sharp service center.